The U.S. patent art illustrates bicycles having both independent and interconnected drives to the front and rear wheels, drives solely for driving the front wheel by one's arms and tandem drives for the rear wheel operable by the bicycler's legs and arms. Representative patents are:
U.S. Pat. No. 5,431,614, granted to Jeranson on Jul. 11, 1995, which illustrates a set of auxiliary handlebars for providing chain and sprocket drive to the front wheel by means of an up-and down arm pumping action through a pair of one way clutches. The front wheel can be driven simultaneously with the rear wheel or independently thereof.
U.S. Pat. No. 5,308,097, granted to Bono on May 3, 1994, which illustrates a reciprocating handlebar operation for a freewheeling front wheel through either a linear or a continuous chain. In essence, Bono teaches a ratcheting-type of drive in which motion is imparted to the wheel while pulling the handlebars toward one's self, but the drive is disconnected during the return stroke of the handlebars and chain to their original positions. The handlebars may be latched in a fixed position whenever the arms are not being used to help propel the bicycle.
U.S. Pat. No. 5,383,676, granted to Valentino on Jan. 24, 1995 shows a tricycle having a drive solely for the front wheel drive. Since a freewheeling front wheel drive similar to a conventional rear wheel drive is used, there is no need for a clutching device to lock the handlebars.
U.S. Pat No. 5,082,302, granted to Nacar on Jan. 21, 1992. This patent illustrates two drives for the rear wheel, one drive being the conventional rear wheel leg pumping drive and the other being an arm cranking drive through a rotation of the handlebars and a second set of chains and sprockets to assist the leg drive to the rear wheel. Overrunning clutches enable freewheeling of either the leg or arm drives.
These and yet other bicycles appear to have found but limited use, perhaps because of their complexity and the attendant cost that goes with complexity.